Which structure (s) is/are primarily responsible for the release of catecholamines?

The correct answer is - adrenal medulla.

Explanation:

The adrenal medulla is the structure that has the cells called chromaffin cells and the postganglionic fibers of the Sympathetic nervous system and brain. Catecholamines are neurotransmitters that include epinephrine, dopamine, and norepinephrine. The secretion or release of the Catecholamines is from the adrenal medulla of the brain.

Thus, the correct answer is - adrenal medulla.